This seems off to me according to the grammar of Ezekiel 28:12-17; for the grammar seems only to describe the "king of Tyrus" himself, not the Garden of Eden at all:
"Son of man, take up a lamentation upon the king of Tyrus, and say unto him, Thus saith the Lord GOD;
1. Thou sealest up the sum, full of wisdom, and perfect in beauty.
2. Thou hast been in Eden the garden of God;
3. every precious stone was THY COVERING, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold:
4. the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
5. Thou art the anointed cherub that covereth; and I have set thee so:
6. thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.
7. Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
8. By the multitude of thy merchandise they have filled the midst of thee with violence, and thou hast sinned:
9. therefore I will cast thee as profane out of the mountain of God: and I will destroy thee, O covering cherub, from the midst of the stones of fire.
10. Thine heart was lifted up because of thy beauty, thou hast corrupted thy wisdom by reason of thy brightness:
11. I will cast thee to the ground, I will lay thee before kings, that they may behold thee."
Grammatically, in verse 13 (as per #2 & #3 above) the description of precious stones is NOT presented as a description for the Garden of Eden. Rather, the description of precious stones is presented as a description of the king of Tyrus' PERSONAL covering. In fact, the only thing that verse 13 says about the Garden of Eden is simply that the king of Tyrus had been in that garden. It says nothing about precious stones as a part of that garden.